In order to meet production requirements of small quantity and large variety for versatile market demands, industrial robots with dexterous end-effectors are usually applied to the flexible manufacturing systems. However, owing to constraints of robot¡¦s accuracy, repeatability, and resolution, assembled parts may experience collision during the insertion process. Both positional and angular errors, which cannot be easily predicted because of indeterminate collision situations, may cause failure of the assembly. One of the frequently applied strategies is to use a passive remote center compliance device. Most traditional remote center compliance (RCC) devices aim to solve insertion difficulty for round peg insertion. This dissertation is devoted to analyze the insertion behavior and develop a new remote center compliance device for square pegs, which lack of the axial symmetry property of round pegs. The presented Passive Multiple Remote Center Compliance Device (MRCC) introduces a new azimuthal compliance over traditional passive compliance mechanisms that can effectively compensate the peg¡¦s orientation deviation for polygonal assembly. Besides, a special feature of the adjustable compliance provides capability to overcome the gravity effect. Non-vertical insertions therefore become possible. A spring-supported object in space is also adopted for stability analysis of the compliant device. Actual experimental assembly processes demonstrate promising results on polygonal insertions in both traditional top-down and horizontal directions. The assembly process of a square peg consists of approach, one-point contact, two-point contact, three-point contact, four-point contact, rotation, departure from chamfer crossing, and insertion. Full analysis of the square peg mating process, using a quasi-static approach will be presented. Constraints that can avoid the jamming and wedging phenomenon for successful assembly will also be established. Furthermore, a novel geometric insertion map, which is able to predict regions of failure and success before actual insertion takes place, is developed to improve efficiency of successful assembly for square pegs.

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Abstract The thesis deals with the US foreign policy under Richard Nixon. More specifically, it examines the US rapprochement with Communist China (PRC) and the triangular diplomatic relations between the US, USSR, and PRC. The thesis draws from the realist theories, particularly the offensive and defensive branches of neorealism represented by John Mearsheimer and Kenneth Waltz. The thesis applies the theoretical concept of wedging strategies as power-balancing tools on the selected US foreign policy. The thesis conducts a qualitative case study using the process-tracing method. A causal mechanism derived from the concept of wedging strategies is theorized and further applied in the analysis. The analysis of the US foreign policy towards China examines the individual traces in the theorized mechanisms. The results of the study show that the US broke the Sino-Soviet alliance using a defensive wedging strategy by exploiting the Sino-Soviet split, resulting in PRC's dealignment with the USSR. The US reapproached the PRC and swayed the Chinese leadership with strategic guarantees tacitly aimed against the USSR. These guarantees were ultimately projected into the Shanghai Communique of 1972.

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